Chat Anywhere versions 2.72 and below allow a remote attacker to add %00 before their nickname which keeps an administrator from being able to ban or kick the user from a room.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/32833/chatanywhere.txt
Source: https://packetstormsecurity.com/files/32833/chatanywhere.txt.html